A typical truck cab includes a door located at the left side of the driver through which he can exit the vehicle, by turning his body to the left and stepping down out of the cab. Another type of cabin that has been developed, includes a rear doorway at the rear of the cab, which is the principle avenue of ingress and egress to the cabin. This arrangement is described in U.S. patent application Ser. No. 351,495 filed Feb. 23, 1982 and Ser. No. 351,497 filed Feb. 23, 1982. When the driver wants to get out of the seat, or sit down while standing to the right of the seat, he finds it difficult to do so. This is because his feet lie at the same level as the floor of the cab, so he cannot easily support himself at a level just under the steering wheel to slide sidewardly under the steering wheel. A seat arrangement that facilitated getting up and sitting down by a driver who is leaving or entering through the rear of the cab, would facilitate operation of the vehicle.